Known bow sights include bow sights with simple pin markers and bow sights with vertically aligned series of pins mounted in a generally annular frame or pin guard that protects the pins, where each such pin corresponds to a particular distance to a target. The archer visually estimates an approximate range to the target and then sights to the target using the aiming pin corresponding to the estimated range. Some sights have light gathering fiber optic filaments which provide a self powered illuminated dot (or “bright site pin”) that the archer sees at the end of each aiming pin. These fiber optic multi-pin sights have greatly improved the utility of such sights in low light or low contrast lighting situations.
Since the range to the target may vary substantially, it is important that the distance for a particular shot be known with some degree of accuracy. The archer typically has to pre-measure or step off the distance to an anticipated target location from the archer's tree stand, blind, or other shooting location. Alternatively he must simply guess as to the approximate distance to the target to compensate for the effects of gravity on an arrow in flight to the target.
To address the problem of inaccuracy in estimating range, a laser rangefinder sight has been marketed by Bushnell of Overland Park, Kans. This rangefinder system has a laser range finding instrument mounted above a multiple pin bow sight. The rangefinder is actuated by a switch that is pressed by the archer's finger when the bow sight is aimed at a target. While the switch is depressed, the rangefinder laser calculates and displays the distance to the target to the archer. The archer then chooses which of several sighting pins to align with the target based on the distance displayed. For example, if the archer has preset the pins to distances of 10, 20, 30, 40, and 50 yards, the archer would choose the pin closest to the displayed target distance. In one model, the Bushnell laser rangefinder is integral with the multiple pin sight. The entire sight may also be removed from the bow and used as a hand held distance measurement device. In another Bushnell model, the rangefinder is modular and may be removed from the bow sight for use as a hand held distance measuring device.
U.S. Pat. No. 6,073,352 to Zykan et al., the entirety of which is hereby incorporated by reference herein, discloses a laser rangefinder bow sight adapted for use with a conventional multi-pin bow sight. When the rangefinder is triggered, the CPU determines the target distance and activates an LED that illuminates the pin or pins that most closely correspond to the measured distance.
Laser rangefinders for bow sights have not met with wide commercial success due to difficulties with mounting, calibrating and accurately aiming the laser rangefinder with respect to the bow sight.